title: Current transport mechanism at metal-semiconductor nanoscale interfaces based on ultrahigh density arrays of p-type NiO nano-pillars.
abstract: The present work focuses on a qualitative analysis of localised I-V characteristics based on the nanostructure morphology of highly dense arrays of p-type NiO nano-pillars (NiO-NPs). Vertically aligned NiO-NPs have been grown on different substrates by using a glancing angle deposition (GLAD) technique. The preferred orientation of as grown NiO-NPs was controlled by the deposition pressure. The NiO-NPs displayed a polar surface with a microscopic dipole moment along the (111) plane (Tasker's type III). Consequently, the crystal plane dependent surface electron accumulation layer and the lattice disorder at the grain boundary interface showed a non-uniform current distribution throughout the sample surface, demonstrated by a conducting AFM technique (c-AFM). The variation in I-V for different points in a single current distribution grain (CD-grain) has been attributed to the variation of Schottky barrier height (SBH) at the metal-semiconductor (M-S) interface. Furthermore, we observed that the strain produced during the NiO-NPs growth can modulate the SBH. Inbound strain acts as an external field to influence the local electric field at the M-S interface causing a variation in SBH with the NPs orientation. This paper shows that vertical arrays of NiO-NPs are potential candidates for nanoscale devices because they have a great impact on the local current transport mechanism due to its nanostructure morphology.
authors.affiliation: CENIMAT/I3N, Departmento de Ciencia dos Materials, Faculdade de Ciencias e Tecnologia, FCT, Universidade Nova de Lisboa and CEMOP-UNINOVA, 2829-516 Caparica, Portugal. snandy_ju@yahoo.co.in emf@fct.unl.pt.
authors.forename: Suman
authors.initials: S
authors.lastname: Nandy
authors.forename: Gonçalo
authors.initials: G
authors.lastname: Gonçalves
authors.forename: Joana Vaz
authors.initials: JV
authors.lastname: Pinto
authors.forename: Tito
authors.initials: T
authors.lastname: Busani
authors.forename: Vitor
authors.initials: V
authors.lastname: Figueiredo
authors.forename: Luís
authors.initials: L
authors.lastname: Pereira
authors.forename: Rodrigo Ferrão
authors.initials: RF
authors.lastname: Paiva Martins
authors.forename: Elvira
authors.initials: E
authors.lastname: Fortunato